If you have 75+ lbs to lose 2 lbs/week is ideal 
If you have 40-75 lbs to lose 1.5 lbs/week is ideal 
If you have 25-40 lbs to lose 1 lbs/week is ideal 
If you have 15 -25 lbs to lose 0.5 to 1.0 lbs/week is ideal 
If you have less than 15 lbs to lose 0.5 lbs/week is ideal